Sometimes in networks, such as wireless networks, it is desirable to allocate network resources according to policies or rules. These policies cover resources such as network bandwidth, Quality of Service (QoS), and security (firewalls). As the content delivered to mobile subscribers (e.g., cell phones, personal digital assistants (PDA), and other handheld devices) becomes more diversified to include Voice over IP (VoIP), streaming media, and multiplayer gaming, these types of content require reliable network connections with fixed parameters. With other types of content, such as email and web surfing, latency and packet loss do not affect the quality of the content delivered as much, and typically the effect is less noticeable. A network with policy-based management uses rules to govern various aspects of the network behavior.
Networks implementing policy-based management typically include a policy decision function and a policy enforcement point. The policy decision function is a resource manager or policy server that is responsible for handling events, making decisions based on those events, and updating the policy enforcement point configuration based on the decisions. The policy enforcement point exists in network nodes such as routers, firewalls, and hosts. The node enforces the policies based on the rule sets received from the policy decision function.